Striking ISIS doesn't prove anything, they're animals which can be useful but they remain animals which you can't trust.
Turkey served as the gateway for global Jihadists to enter Syria. The foreigners that have ended up in Syria and Iraq are came through Turkey, their quantity makes it impossible that those all slipped through border security. Turkey has control over it's borders and they allowed them in. No Jihadists entered Syria through Jordan which is far less militarily advanced than Turkey.
Hear it from Biden himself.
You all forget, Erdogan is ruling Turkey, he's an Islamist allied to Qatar which has been accused often of funding ISIS by many including the German minister and General Dempsey. State media of Qatar, Al Jazeera ( the Arabic version ) is the propaganda machine of ISIS, they call their suicide bombings martyrdom operations. Egypt just accused Qatar of funding terrorism.
Just because Turkey has struck ISIS and ISIS has kidnapped Turks proves nothing, if Turkey let them through and helped them it doesn't have to mean that Turkey and ISIS are allies. ISIS like groups are animals which can be useful for you only if they don't attack you but attack your enemy ( Syria under Bashar for Erdogan/PKK ) that's what the ties have been like. This open border policy of Turkey has been going on for several years say 2011. ISIS has grown quickly in Syria since, they took control of Al Raqqa only a year and several months ago. Now they're of no benefit anymore, they've destroyed the FSA in Eastern Syria and the entire revolutionary dream among locals more than anyone else could, the group has become a threat even for Turkey therefor they've changed their stance towards ISIS. But that doesn't change Erdogan's history of supporting them previously.
Currently he's playing another game in Egypt ignoring the terrorist groups over there and promoting uprisings. He's gone on a path not any different than post 1979 Iran. If we look at history Saudis used to sponsor the same kind of group to fight Soviets, Pakistan as well. Both have been attacked by them in return. Pakistan suffering till this day by a group with a similar ideology to TTP they used to support against Soviets. Politicians play dirty games after all, we've seen this done by many in the ME and elsewhere. Syria under Bashar pre 2010 used to help ISI ( Islamic state Iraq back then ) in Iraq, it backfired eventually. This thread is news about ISIS threat in Turkey, same backfiring is always possible through bombings esp. for neighbors.
I'm saying this as this is what it looks like to me, not out of any emotions. If someone can show me wrong i'd be glad to learn.